JPH0745830B2 - Supercharging pressure controller for engine with supercharger - Google Patents

Description

TECHNICAL FIELD The present invention relates to an improvement of a supercharging pressure control device for a supercharged engine.

(Prior Art) Conventionally, in a supercharged engine, a waste gate valve is driven by a drive device (duty solenoid, diaphragm, etc.) in a high load region (supercharging region) to control supercharging pressure. A supply pressure control device has been proposed (see Japanese Patent Publication No. 59-49408).

According to this device, since the drive device, particularly the duty solenoid, is not operated in the low load region (non-supercharging region), the durability is improved.

By the way, if the engine knocks,
This can be dealt with by ignition timing control or the like. However, since knocking due to the supercharging pressure also occurs in the high load and high rotation range, in this case, it is necessary to drive the waste gate valve by a duty solenoid or the like to control the supercharging pressure.

However, since the duty solenoid does not operate in the low load region, if the duty solenoid is operated by calculating the control amount of the wastegate valve after entering the high load region, the response of the supercharging pressure control will be reduced. Since it worsens, there was a problem that knocking occurred during the delay in response and engine damage increased.

(Object of the Invention) The present invention has been made in order to solve the above-mentioned conventional problems, and when entering a high load range without impairing the durability of the drive device (duty solenoid) of the supercharging pressure adjusting means. It is intended to improve the responsiveness of the supercharging pressure control of.

(Structure of the Invention) Therefore, the present invention, as shown in FIG.
The supercharger B for supercharging the intake air supplied to the engine A, the load detecting means C for detecting the load state of the engine A, the supercharging pressure adjusting means D for adjusting the supercharging pressure, and the knocking of the engine A The engine load is lower than a predetermined load for adjusting the supercharging pressure by the supercharging pressure adjusting means D by receiving the knocking detecting means E for detecting and the outputs of the load detecting means C and the knocking detecting means E, and the knocking occurs. When detected, a boost pressure control value calculation means F for calculating a control value for controlling the boost pressure, and a control value calculated by the boost pressure control value calculation means F when the engine load is lower than the predetermined load. The engine load becomes equal to or higher than the predetermined load in response to the outputs of the control value reflection control means H for limiting the reflection of the supercharging pressure adjusting means D to the supercharging pressure adjusting means D, the load detecting means C and the supercharging pressure control value calculating means F. When the engine Control value reflection unit load lowers the boost pressure adjustment means boost pressure to reflect the control value calculation to modulation of the supercharging pressure by D when lower than the predetermined load G
It is characterized by having and.

(Effect of the Invention) According to the present invention, the load detected by the load detecting means is equal to or less than the predetermined load for which the supercharging pressure adjusting means should adjust the supercharging pressure, that is, in the low load range, and the knocking detecting means knocks Is detected, the control value for controlling the supercharging pressure is calculated in advance by the supercharging pressure control value calculating means, and when the load exceeds the predetermined load, that is, in the high load region, the control value reflecting means performs arithmetic control. Since the value is reflected in the adjustment of the supercharging pressure by the supercharging pressure adjusting means, the driving device (duty solenoid) of the supercharging pressure adjusting means is inoperative in the low load range, so that the durability is deteriorated. When the high load region is entered, the drive device (duty solenoid) of the supercharging pressure adjusting means can be operated by reflecting the control value calculated in advance in the low load region. Improving responsiveness of pressure control Become so.

When the engine load is lower than the predetermined load, the control value control means limits the reflection of the control value to the supercharging pressure adjusting means.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 2, the engine 1 (A) is composed of a cylinder block 2 and a cylinder head 3.

A piston 4 is fitted in the cylinder block 2 and a combustion chamber 5 is formed above the pistun 4.

The cylinder block 2 has a knocking detection sensor 6
(E) and the engine speed detection sensor 7 are provided.

The cylinder head 3 has an intake port 8 and an exhaust port 9
Are formed, and the intake port 10 has an intake valve 10 and the exhaust port 9 has
An exhaust valve 11 is provided in each of these.

An intake passage 13 is connected to the intake port 8 and
An air cleaner 14, an air flow meter 15 for detecting the intake air amount Q, a compressor 16a of the exhaust turbocharger 16 (B), a throttle valve 17, and a fuel injection valve 18 are provided on the upstream side 13 from the upstream side to the downstream side. Has been.

An exhaust passage 20 is connected to the exhaust port 9, and the exhaust passage 20 is provided with a turbine 16b of an exhaust turbocharger 16 (B) and a catalyst 21 from upstream to downstream. .

A bypass passage 22 is provided between the exhaust passage 20 between the upstream side and the downstream side of the turbine 16b, and the waste passage valve whose opening and closing is controlled by the diaphragm 23 in the bypass passage 22.
24 are installed.

The diaphragm 23 is responsive to intake negative pressure in the intake passage 13 by a first negative pressure passage 25 connected between the compressor 16a of the intake passage 13 and the throttle valve 17 and is a wastegate valve.
The opening and closing of 24 will be controlled.

The first negative pressure passage 25 and the compressor 16a of the intake passage 13
The air flow meter 15 and the air flow meter 15 are connected by a second negative pressure passage 26, and a duty solenoid 27 is provided in the second negative pressure passage 26.

The diaphragm 23, the waste gate valve 24, the duty solenoid 27, etc. constitute a boost pressure adjusting means (D).

The knocking detection sensor 6 (E), the engine speed detection sensor 7, the air flow meter 15, the opening sensor 29 of the throttle valve 17, the duty solenoid 27, etc. are connected to the on-vehicle microcomputer 28.

The microcomputer 28 has a program, which will be described below with reference to a flowchart, incorporated therein. When the program is grasped as hardware, the load state of the engine 1 (A) is calculated from the engine speed N and the intake air amount Q. Receiving the outputs of the load detection circuit (C) for detecting the load, the load detection circuit (C) and the knocking sensor 6 (E), the load is boosted by the boost pressure adjusting means 23, 24, 27 (D). Less than a predetermined load, that is, low load range L (see FIG. 4)
And when knocking is detected, a boost pressure control value calculation circuit (F) for calculating a control value for controlling the boost pressure, the load detection circuit (C) and the boost pressure control value calculation circuit (F). )
Is received, the predetermined load or more, that is, the high load range H (4th
(See the figure), a control value reflecting circuit (G) for reflecting the calculated control value and reducing the supercharging pressure by the supercharging pressure adjusting means 23, 24, 27 (D) is provided. Is equivalent to being

Therefore, when the load detection circuit (C) detects that the load is in the low load range L and the knocking detection sensor 6 (E) detects knocking, the supercharging pressure control value calculation circuit (F) precharges the supercharged pressure. The control value for controlling the pressure is calculated, and when the high load region H is reached, the calculated control value is reflected by the control value reflecting circuit (G) and the boost pressure adjusting means 23, 24, 27 (D) is used. It will reduce the boost pressure.

Therefore, in the low load region L, the duty solenoid 27 of the supercharging pressure adjusting means (D) is inoperative, so durability is not impaired. When the high load area H is entered, the low load area L
Since it is possible to operate the duty solenoid 27 of the supercharging pressure adjusting means (D) by reflecting the control value calculated in advance, the responsiveness of the supercharging pressure control is also improved.

Next, the boost pressure control method will be described based on the flowchart of FIG.

It starts at step S1 and reads engine speed N and intake air amount Q at step S2.

In step S3, it is determined whether or not the load is equal to or more than the first set load a (the ultra-low load region 1 in the low load region L where knocking is unlikely to occur ... See FIG. 4). For example, knocking is detected in step S4, and it is determined whether knocking has occurred in step S5. If NO, the second set load b (the boundary between the low load region L and the high load region H ...
(See FIG. 4) It is determined whether or not the above, and if YES, the open / close control of the wastegate valve 24 is performed through the diaphragm 23 by the intake load in step S9 '.

If YES in step S5, the ignition timing is retarded to control knocking in step S6. At the same time, in step S7, a control value for controlling the supercharging pressure by the waste gate valve 24 is calculated and stored in advance.

Next, in step S8, it is determined whether or not the load is equal to or more than the second set load b.
Then, the duty solenoid 27 is driven by reflecting the calculation control value stored in step S7.
The waste gate valve 24 is opened and closed by the diaphragm 27 via the diaphragm 23.

[Brief description of drawings]

1 is a configuration diagram of the present invention, FIG. 2 is a configuration diagram of a supercharging pressure control device for an engine with a supercharger according to the present invention, FIG. 3 is a flowchart of the device of FIG. 2, and FIG. 4 is a load. It is a graph which shows a range. 1 (A) ... Engine, 16 (B) ... Turbocharger, C ... Load detection circuit, 23,24,27 (D) ... Supercharging pressure adjustment control means, 6 (E) ... Knocking Detection sensor, F ... Boost pressure control value calculation circuit, G ... Control value reflection circuit.

Claims (1)

[Claims] 1. A supercharger for supercharging intake air supplied to an engine, load detecting means for detecting a load state of the engine, supercharging pressure adjusting means for adjusting a supercharging pressure, and knocking of the engine. When the engine load is lower than a predetermined load for adjusting the boost pressure by the boost pressure adjusting means, and knocking is detected, the output of the knock detecting means and the output of the load detecting means and the knock detecting means, To a boost pressure control value calculating means for calculating a control value for controlling the boost pressure and to a boost pressure adjusting means for the control value calculated by the boost pressure control value calculating means when the engine load is lower than the predetermined load. When the engine load becomes equal to or higher than the predetermined load by receiving the output of the control value reflection limiting means for limiting the reflection of the engine load, the load detection means and the boost pressure control value calculation means, the engine load becomes the predetermined load. An engine with a supercharger, comprising: a control value reflecting unit that reflects the control value calculated in the adjustment of the supercharging pressure by the supercharging pressure adjusting unit when the load is lower than the load to reduce the supercharging pressure. Boost pressure control device.